Funding for this research was provided by:
Narodowe Centrum Nauki (74/MN/INB/2015)
Received: 6 March 2020
Accepted: 4 November 2020
First Online: 11 November 2020
Ethics approval and consent to participate
: The study protocol was approved by the Ethics Commission at the District Medical Chamber (K.B. no. 114/KBL/OIL/2014). The participants were familiarised with the purpose and content of the study, and were informed that they could withdraw at any time without having to state the reason. All participants completed and submitted signed consent forms.
: Not applicable.
: The authors declare that they have no competing interests.